Program accounting with ledger marks
The resource usage of a program run is recorded in two accounting records at the start and at the end of the program. These records contain the current state of the usage values (ledger mark) since the start of the task run.
The accounting system divides each task run into the events “task start”, “program start”, “program end”, and “task end”. By determining differences between these event data, an analysis program can calculate both the resource usage of the program and the usage data of the command mode occurring between two programs. For accurate accounting of long-running programs, the accounting system also provides a third record which periodically writes data to the accounting file and gives information on the average usage values during runtime.
Accounting data for user accounting
For user accounting the accounting system makes available a set of accounting data which are explained in the detailed description of the records in the appendix. The following information is provided for a user ID:
Data on the basic resources
CPU time
I/O system (number of transported blocks or bytes)
main memory (working set integral)
service units (sum of the individual values of CPU time, I/O and main memory, takes into account CPU performance)
Extended device usage data with time stamp and device type
Volume usage data
Job information and task execution information
Extended program information
internal program name
reason for termination
memory usage integral for class 5 and class 6 memory
SPOOLOUT information
type of output device
number of printed lines and pages
Accounting of storage space changes
Space accounting
For accounting of permanent storage space usage on public and private disks, the accounting system provides an interface that permits recording on the basis of samples. These samples can be controlled by a user program (via the ASPC macro) under the privileged user ID of systems support. The ASPC macro writes one or more accounting records in the accounting file for each locally available pubset, every record containing
the catalog ID of the pubset
the time the record was written
an indicator of record integrity
the user IDs of the pubset
the number of reserved PAM blocks per user ID.
The ASPC macro is described in the “Executive Macros” manual [30].
These data records can also be periodically recorded in the accounting file. The parameters for such cyclical monitoring and recording are controlled by systems support with appropriate specifications at the command level.
operations accounting
The availability of the entire system is documented by an accounting open record and an accounting close record. The open record is written after an accounting file has been opened, the close record is written before the accounting file is closed in the prescribed way. The identification section and basic information of these records contain:
the designation of the server
the system name and system version
an identifier for startup or shutdown
Whenever the accounting file is changed, the new file is given a reference with respect to its predecessor. The availability of the CPU resource is documented in records which are written periodically and which contain the task (TU + TPR), interrupt handling (SIH) and IDLE times of the CPU. The main memory size is recorded in the first accounting open record, either during system initialization or after a START-ACCOUNTING command.
Accounting of system services in computer center tasks
A task is the largest unit that is monitored for purposes of user accounting.
System functions which are executed in a system task or on another server and which use an appreciable amount of resources are recorded in separate accounting records.
The following services requested by the user are recorded in appropriate service units:
spoolout
User dumps
RFA links
For system functions whose resource usage for a given job is relatively small but which are called frequently, the service units are integrated in the entries of the task and program accounting records, e.g.:
number of disk input/output operations
number of terminal input/output operations
number of catalog accesses
The accounting records are shown in the tables starting on "Overviews of accounting records".